<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>计数器</title>
	</head>
	<body>
		
		<div id='app'>
			<div class="input-num">
				<button @click="sub">
					-
				</button>
				<span>{{ num }}</span>
				<button @click="add">
					+
				</button>
			</div>
		</div>
		
		 <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
		<script>	 
		var vm = new Vue({
				 el: "#app",
				 data:{
					 num:1
				 },
				 methods: {
					 add:function(){
						 //console.log('add');
						 if(this.num<10){ 
						 this.num++;
						 }else{ 
							 alert('不能再大了');
							 }
					 },
					 sub:function(){
						 //console.log('sub');
						 if(this.num>0){ 
						 this.num--;
						 }else{ 
							 alert('不能再小了')
							 }
					 }
				 },
			 })
	    
		
		 </script>
	</body>
</html>
